Display device and method of manufacturing the same

ABSTRACT

A display device and a method of manufacturing the same are disclosed, in which a sensing electrode for sensing a touch of a user is built in a display panel, whereby a separate touch screen is not required on an upper surface of the display panel and thus thickness and manufacturing cost are reduced.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the Korean Patent Application No.10-2013-0115382 filed on Sep. 27, 2013, which is incorporated byreference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a display device, and moreparticularly, to a display device provided with a sensing electrode forsensing a touch of a user.

2. Discussion of the Related Art

Various display devices such as a liquid crystal display device, aplasma display panel, and an organic light emitting display device havebeen developed.

Traditional display devices often include a mouse and a keyboard asinput means. However, a touch screen, that allows a user to directlyinput information by using his/her finger or pen is often utilized indevices such as navigation systems, a portable terminals, and homeappliances.

Hereinafter, a liquid crystal display device to which a touch screen isapplied will be described in detail.

FIG. 1 is a brief cross-sectional view illustrating a liquid crystaldisplay of the related art.

As shown in FIG. 1, the liquid crystal display device of the related artincludes a liquid crystal panel 10 and a touch screen 20.

The liquid crystal panel 10 displays images, and includes a lowersubstrate 12, an upper substrate 14, and a liquid crystal layer 16formed between these substrates 12 and 14.

The touch screen 20 is formed on an upper surface of the liquid crystalpanel 10 to sense a touch of a user, and includes a touch substrate 22,a first sensing electrode 24 formed on a lower surface of the touchsubstrate 22, and a second sensing electrode 26 formed on an uppersurface of the touch substrate 22.

The first sensing electrode 24 is arranged on the lower surface of thetouch substrate 22 in a horizontal direction, and the second sensingelectrode 26 is arranged on the upper surface of the touch substrate 22in a vertical direction. Accordingly, if the user touches apredetermined position, capacitance between the first sensing electrode24 and the second sensing electrode 26 is varied at the touchedposition. As a result, the position where capacitance is varied issensed, whereby the touch position of the user may be sensed.

However, since the aforementioned liquid crystal display device of therelated art has a structure in which the touch screen 20 is separatelyformed on the upper surface of the liquid crystal panel 10, the overallthickness of the display device is increased due to the touch screen 20and the manufacturing cost is also increased.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a display device and amethod of manufacturing the same, which substantially obviate one ormore problems due to limitations and disadvantages of the related art.

An advantage of the present invention is to provide a display device anda method of manufacturing the same, in which a sensing electrode forsensing a touch of a user is built in a display panel, whereby aseparate touch screen is not required on an upper surface of the displaypanel. Thus, thickness and manufacturing costs are reduced.

Additional advantages and features of the invention will be set forth inthe description which follows and will be apparent to those havingordinary skill in the art upon reading this disclosure. The objectivesand other advantages of the invention may be realized and attained bythe structure particularly pointed out in the written description andclaims hereof as well as the appended drawings.

To achieve these objects and other advantages as embodied and broadlydescribed herein, a display device according one embodiment comprises athin film transistor formed in a pixel region comprising a gate line anda data line crossing the gate line, the thin film transistor including agate electrode, a semiconductor layer, a source electrode, and a drainelectrode; a first passivation film formed on the thin film transistor;a second passivation film formed on the first passivation film, thefirst and second passivation films structured such that a hole existsthrough the first and second passivation films that at least partiallyexposes the source electrode and the drain electrode from the first andsecond passivation films; a pixel electrode formed on the secondpassivation film and at least partially filling the hole through thefirst and second passivation films, the pixel electrode connected withthe drain electrode via the hole through the first and secondpassivation films; a sensing line formed on the second passivation film;a common electrode connected with the sensing line; a data pad connectedwith one end of the data line; a first connection electrode formed onthe data pad and connected with the data pad; a second connectionelectrode formed on the first connection electrode and connected withthe first connection electrode; and a data pad electrode formed of asame material as the common electrode, the data pad electrode connectedwith the data pad through the first connection electrode and the secondconnection electrode.

In another embodiment, a method of manufacturing a display devicecomprises the steps of sequentially forming a first semiconductor layerand a source/drain electrode layer on a surface of a substrate on whicha gate electrode and a gate insulating film are formed; simultaneouslypatterning the semiconductor layer and the source/drain electrode layerto form a first pattern in a thin film transistor region and to form asecond pattern in a data pad region, the first pattern comprising afirst portion of the semiconductor layer and a first portion of thesource/drain electrode layer, and the second pattern comprising a secondportion of the semiconductor layer and a data pad formed from a secondportion of the source/drain electrode layer; sequentially forming firstand second passivation films such that a hole exists through the firstand second passivation films through which at least a part of thesource/drain electrode layer is exposed in the thin film transistorregion including the first pattern; sequentially forming a secondmaterial layer and a third material layer on the second passivationfilm; forming a sensing line pattern, a pixel electrode pattern, and aconnection electrode pattern connected with the data pad by patterningthe second and third material layers through a patterning process usinga half tone mask; forming a third passivation film on the sensing linepattern, the pixel electrode pattern, and the connection electrodepattern; and forming a common electrode connected with the sensing linepattern and a data pad electrode connected with the connection electrodepattern on the third passivation film.

In another embodiment, a display device comprises: a thin filmtransistor formed in a pixel region comprising a gate line and a dataline crossing the gate line, the thin film transistor comprising a gateelectrode, a semiconductor layer, a source electrode, and a drainelectrode; a first passivation film formed on the thin film transistor;a second passivation film formed on the first passivation film, thefirst and second passivation films structured such that a hole existsthrough the first and second passivation films that at least partiallyexposes the drain electrode from the first and second passivation films;a pixel electrode formed on the second passivation film and the drainelectrode and at least partially filling the hole through the first andsecond passivation films, the pixel electrode connected with the drainelectrode via the hole through the first and second passivation films; asensing line formed on the second passivation film; a common electrodeconnected with the sensing line; a data pad connected with one end ofthe data line; and a data pad electrode formed of a same material as thecommon electrode, the data pad electrode connected with the data pad.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate embodiments of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a brief cross-sectional view illustrating a liquid crystaldisplay of the related art;

FIG. 2 is a brief plane view illustrating a substrate for a displaydevice according to one embodiment of the present invention;

FIG. 3 is a brief plane view illustrating a lower substrate for a liquidcrystal display device according to another embodiment of the presentinvention;

FIG. 4 is a cross-sectional view illustrating a display device accordingto the first embodiment of the present invention;

FIGS. 5 a to 5 i are brief cross-sectional views illustratingmanufacturing process steps of a substrate for a display deviceaccording to the first embodiment of the present invention;

FIGS. 6 a to 6 c are cross-sectional views illustrating occurrence ofunder cut in a display device according to the first embodiment of thepresent invention;

FIG. 7 is a cross-sectional view illustrating a display device accordingto the second embodiment of the present invention;

FIGS. 8 a to 8 j are brief cross-sectional views illustratingmanufacturing process steps of a substrate for a display deviceaccording to the second embodiment of the present invention;

FIG. 9 is a cross-sectional view illustrating an organic insulatingmaterial remaining in a display device according to the secondembodiment of the present invention;

FIG. 10 is a cross-sectional view illustrating a display deviceaccording to the third embodiment of the present invention; and

FIGS. 11 a to 11 g are brief cross-sectional views illustratingmanufacturing process steps of a substrate for a display deviceaccording to the third embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the exemplary embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

The term “on” is used herein to describe an element directly in contactwith another element, or to describe an element that is positioned overanother element (in a cross-sectional view) with one or more interveningelements in between.

The terminologies such as “first” and “second” disclosed in thisspecification do not mean the order of corresponding elements and areintended to identify the corresponding elements from each other.

Hereinafter, the embodiment of the present invention will be describedwith reference to the accompanying drawing.

FIG. 2 is a brief plane view illustrating a substrate for a displaydevice according to one embodiment of the present invention. Forreference, an enlarged view shown by an arrow in FIG. 2 is intended toshow a pixel region where a sensing line 600 and a common electrode 700are electrically connected with each other.

As shown in FIG. 2, the display device according to one embodiment ofthe present invention includes a substrate 100, a gate line 200, a dataline 300, a thin film transistor T, a pixel electrode 500, a sensingline 600, a common electrode 700, a driving integrated circuit 1, a gatein panel 2, and a touch driver 3. The gate in panel 2 comprises a gatedriving circuit integrated with a panel.

The substrate 100 may be made of glass or transparent plastic.

The gate line 200 is arranged on the substrate 100 in a first direction,for example, a horizontal direction. One end of the gate line 200 isconnected with the gate in panel 2, and the gate in panel 2 is connectedwith the driving integrated circuit 1 through a gate pad 215.Accordingly, a gate signal applied from the driving integrated circuit 1is transferred to the gate line 200 through the gate pad 215 and thegate in panel 2.

The data line 300 is arranged on the substrate 100 in a second directiondifferent from the first direction, for example, a vertical direction.In this way, the gate line 200 and the data line 300 are arranged tocross each other, whereby a plurality of pixel regions are defined. Oneend of the data line 300 is connected with the driving integratedcircuit 1 through a data pad 315. Accordingly, a data signal appliedfrom the driving integrated circuit 1 is transferred to the data line300 through the data pad 315. Although the data line 300 is arranged ina straight line as shown, the data line 300 may be arranged in a curvedline or a pattern of curved and/or straight line such as a zigzag shape.

The thin film transistor T is a switching element, and is formed in eachof the plurality of pixel regions. Although not shown in detail, thethin film transistor includes a gate electrode connected with the gateline 200, a semiconductor layer serving as a channel to which electronsare moved, a source electrode connected with the data line 300, and adrain electrode formed to face the source electrode. This thin filmtransistor T may be formed in various shapes known in the art, such as atop gate structure and a bottom gate structure.

The pixel electrode 500 is patterned in each of the plurality of pixelregions. This pixel electrode 500 is connected with the drain electrodeof the thin film transistor T.

Since the sensing line 600 is connected with the common electrode 700,the sensing line 600 serves to transfer a touch signal of a user, whichis sensed by the common electrode 700, to the touch driver 3. Totransfer the touch signal of the user, a plurality of sensing lines 600are connected with a plurality of common electrodes 700 in pairs. Inother words, each of the plurality of sensing lines 600 is connectedwith each of the plurality of common electrodes 700 in a one-to-oneconfiguration.

In order to prevent light transmittance from being reduced by thesensing line 600, the sensing line 600 is formed over the data line 300.

In one embodiment, the sensing line 600 includes a contact portion 600 aextended towards the thin film transistor T region, whereby the sensingline 600 may be connected with the common electrode 700 through thecontact portion 600 a. The thin film transistor T region is the regionwhere image is not displayed, and is wider than the data line 300.Accordingly, if the contact portion 600 a is formed to connect with thecommon electrode 700 at the thin film transistor T region, a morereliable connection between the sensing line 600 and the commonelectrode 700 may be made without reduction of light transmittance. Inother words, since the sensing line 600 and the common electrode 700 areconnected with each other through a predetermined contact hole, forreliable connection between them, the width of the sensing line 600 ispreferably a predetermined range or more. Accordingly, the contactportion 600 a is formed to have a width greater than that of the dataline 300, whereby the sensing line 600 and the common electrode 700 maybe connected with each other more reliably.

In other embodiment, the sensing line 600 does not include the contactportion 600 a, and at least a part of the sensing line 600 mayelectrically be connected with the common electrode 700.

For convenience of description, the following embodiments are describedin the context of a device in which the sensing line 600 includes thecontact portion 600 a and is electrically connected with the commonelectrode 700 through the contact portion 600 a.

The common electrode 700 serves as a sensing electrode that senses atouch position of the user. Also, in case of the liquid crystal displaydevice, the common electrode 700 serves to drive a liquid crystal byforming electric field together with the pixel electrode 500. Namely,the common electrode 700 may form a fringe field together with the pixelelectrode 500. To this end, the common electrode 700 is provided with aplurality of slits 710. Accordingly, the fringe field is formed betweenthe pixel electrode 500 and the common electrode 700 through the slits710, and an alignment direction of the liquid crystal may be adjusted bythe fringe field. In other words, a fringe field switching mode liquidcrystal display device may be obtained.

Also, in order that the common electrode 700 serves as the sensingelectrode for sensing the touch position of the user, the plurality ofcommon electrodes 700 are spaced apart from one another on the substrate100 at a predetermined distance. Each of the plurality of commonelectrodes 700 is formed at a size corresponding to one or more pixelregions, particularly a size corresponding to the plurality of pixelregions considering a touch area of the user.

After the driving integrated circuit 1 receives a gate control signalfrom a timing controller (not shown), the driving integrated circuit 1applies the gate signal to the gate line 200 through the gate pad 215and the gate in panel 2.

Also, after the driving integrated circuit 1 receives a data controlsignal from a timing controller (not shown), the driving integratedcircuit 1 applies the data signal to the data line 300 through the datapad 315.

The gate in panel 2 applies the gate signal transferred from the drivingintegrated circuit 1 to the gate line 200, and may be formed in anon-display region of a left side and/or right side of the substrate 100by a gate in panel (GIP) method together with a manufacturing process ofa transistor of each pixel. In another embodiment, the gate in panel 2may be formed in a structure of a tape carrier package (TCP) or chip onfilm (COF), or may be formed in a structure of chip on glass (COG) wherethe gate in panel 2 is packaged on the substrate 100.

Since the touch driver 3 is connected with the sensing line 600, thetouch driver 3 receives a touch signal of the user from the sensing line600. The touch driver 3 detects whether a touch of the user is made anddetects a touch position of the user by sensing variations incapacitance caused by the touch of the user.

FIG. 3 is a brief plane view illustrating a lower substrate for a liquidcrystal display device according to another embodiment of the presentinvention. The liquid crystal display device of FIG. 3 is the same asthe display device of FIG. 2 except for the sensing line 600.Accordingly, the same reference numbers will be used throughout thedrawing to refer to the same parts, and repeated description of the sameparts will be omitted.

As shown in FIG. 3, according to another embodiment of the presentinvention, a plurality of sensing lines 600 are connected with aplurality of common electrodes 700 in a one-to-one configuration.Particularly, the plurality of sensing lines 600 are arranged on adisplay region where images are displayed, at the same length as oneanother.

According to the aforementioned display device of FIG. 2, one end of thesensing line 600 is extended to the touch driver 3 through the drivingintegrated circuit 1, and the other end of the sensing line 600 isconnected with the contact portion 600 a. Namely, according to FIG. 2,the sensing line 600 is extended to the contact portion 600 a connectedwith the common electrode 700, whereby the length of the sensing line600 connected with the common electrode 700 arranged in the first columnis longer than that of the sensing line 600 connected with the commonelectrode 700 arranged in the second column.

By contrast, according to the display device of FIG. 3, one end of thesensing line 600 is connected with the touch driver 3 through thedriving integrated circuit 1, and the other end of the sensing line 600is extended to a top end of the common electrode 700 arranged in thefirst column. Accordingly, in FIG. 3, the sensing line 600 connectedwith the common electrode 700 arranged in the first column is formed inthe display region to have the same length as that of the sensing line600 connected with the common electrode 700 arranged in the secondcolumn.

If the plurality of sensing lines 600 are formed in the display regionat the same length as one another as shown in FIG. 3, pattern uniformityof the sensing lines 600 is greater than the case where the plurality ofsensing lines 600 are formed in the display region at lengths differentfrom one another as shown in FIG. 2, whereby visibility may be improved.

Hereinafter, the display device according to the embodiments of thepresent invention will be described in more detail through a sectionalstructure.

First Embodiment

FIG. 4 is a cross-sectional view illustrating a display device accordingto the first embodiment of the present invention, and illustratescross-sections of lines A-A, B-B and C-C of FIG. 2. The line A-A of FIG.2 illustrates a thin film transistor region, the line B-B of FIG. 2illustrates a gate pad region, and the line C-C of FIG. 2 illustrates adata pad region.

As shown in FIG. 4, a gate electrode 210 and a gate pad 215 are formedon a substrate 100. The gate electrode 210 is formed in the thin filmtransistor region, and the gate pad 215 is formed in the gate padregion. The gate electrode 210 may be extended from the aforementionedgate line 200, and the gate pad 215 is connected with one end of thegate line 200 through a gate in panel 2.

A gate insulating film 220 is formed on the gate electrode 210 and thegate pad 215. The gate insulating film 220 is formed on an entiresurface of the substrate except for a third contact hole CH3 region.

A semiconductor layer 230 and a data pad 315 are patterned on the gateinsulating film 220. The semiconductor layer 230 is formed in the thinfilm transistor region, and may be made of a silicon based semiconductormaterial or oxide semiconductor material. The data pad 315 is formed inthe data pad region, and is connected with one end of the aforementioneddata line 300.

A source electrode 310 and a drain electrode 320 are patterned on thesemiconductor layer 230. The source electrode 310 and the drainelectrode 320 are formed in the thin film transistor region. The sourceelectrode 310 is connected with the data line 300, and the drainelectrode 320 is spaced apart from the source electrode 310 while facingthe source electrode 310.

A first passivation film 410 is formed on the data line 300, the sourceelectrode 310, and the drain electrode 320. The first passivation film410 is formed at a region except for a first contact hole CH1 region inthe thin film transistor region, and is not formed in the gate padregion in which the gate pad 215 is formed and the data pad region inwhich the data pad 315 is formed. The first passivation film 410 may bemade of an inorganic insulating material such as a silicon nitride or asilicon oxide.

A second passivation film 420 is formed on the first passivation film410. The second passivation film 420 is formed in the thin filmtransistor region. The second passivation film 420 may be omitted from(i.e., not formed in) the gate pad region and the data pad region. Thesecond passivation film 420 may be made of an organic insulatingmaterial such as acrylic resin, which includes a photo active compound(PAC). The second passivation film 420 may be formed at a thicknessthicker than that of the first passivation film 410 and may serve toplanarize the substrate.

The first passivation film 410 and the second passivation film 420 arestructured such that a first contact hole CH1 exists through the firstpassivation film 410 and the second passivation film 410 that at leastpartially exposes the drain electrode from the first passivation film410 and the second passivation film 420.

A pixel electrode 500 is patterned on the second passivation film 420and at least partially filling the first contact hole CH1 hole throughthe first and second passivation films. The pixel electrode 500 isformed in the thin film transistor region. The pixel electrode 500 isconnected with the drain electrode 320 through a first contact hole CH1.The first contact hole CH1 is made of combination of holes respectivelyformed in the first passivation film 410 and the second passivation film420.

A third passivation film 430 is formed on the pixel electrode 500. Thethird passivation film 430 is formed on the entire surface of thesubstrate except for regions for a third contact hole CH3 and a fourthcontact hole CH4. The third passivation film 430 may be made of aninorganic insulating material such as a silicon nitride or a siliconoxide.

A sensing line 600 provided with a contact portion 600 a is patterned onthe third passivation film 430. The sensing line 600 is formed in thethin film transistor region.

A fourth passivation film 440 is formed on the sensing line 600. Thefourth passivation film 440 is formed on the entire surface of thesubstrate except for regions for a second contact hole CH2, the thirdcontact hole CH3, and the fourth contact hole CH4. The fourthpassivation film 440 may be made of an inorganic insulating materialsuch as a silicon nitride or a silicon oxide.

A common electrode 700, a gate pad electrode 750, and a data padelectrode 760 are patterned on the fourth passivation film 440. Thecommon electrode 700 is formed in the thin film transistor region, thegate pad electrode 750 is formed in the gate pad region, and the datapad electrode 760 is formed in the data pad region.

The common electrode 700, the gate pad electrode 750, and the data padelectrode 760 are formed on one layer by using one material by oneprocess.

The common electrode 700 is patterned to be provided with a plurality ofslits 710 therein. The common electrode 700 is connected with thecontact portion 600 a of the sensing line 600 through the second contacthole CH2 provided in the fourth passivation film 440.

The gate pad electrode 750 is connected with the gate pad 215 throughthe third contact hole CH3 formed by combination of holes respectivelyformed in the gate insulating film 220, the third passivation film 430,and the fourth passivation film 440.

The data pad electrode 760 is connected with the data pad 315 throughthe fourth contact hole CH4 formed by combination of holes respectivelyformed in the third passivation film 430 and the fourth passivation film440.

FIGS. 5 a to 5 i are brief cross-sectional views illustratingmanufacturing process steps of a substrate for a display deviceaccording to the first embodiment of the present invention, and relateto a process of manufacturing a substrate for the display device shownin FIG. 4.

As shown in FIG. 5 a, the gate electrode 210 and the gate pad 215 arepatterned on the substrate 100. The gate electrode 210 is formed in thethin film transistor region, and the gate pad 215 is formed in the gatepad region.

The gate electrode 210 and the gate pad 215 may be patterned through aseries of mask processes such as photoresist deposition, exposure,developing, etching, and strip after a thin film layer is deposited onthe substrate 100 by a sputtering method. A process of forming patternsof elements, which will be described hereinafter, may also be performedthrough the deposition of the thin film layer and the series of maskprocesses.

Next, as shown in FIG. 5 b, the gate insulating film 220 is formed onthe gate electrode 210 and the gate pad 215, and the semiconductor layer230 is patterned on the gate insulating film 220. The gate insulatingfilm 220 is formed on the entire surface of the substrate by a plasmaenhanced chemical vapor deposition (PECVD) method, and the semiconductorlayer 230 is formed in the thin film transistor region.

Next, as shown in FIG. 5 c, the source electrode 310 and the drainelectrode 320, which are connected with the data line 300, are patternedon the semiconductor layer 230 and the data pad 315 is patterned on thegate insulating film 220.

The source electrode 310 and the drain electrode 320 are formed in thethin film transistor region, and the data pad 315 is formed in the datapad region.

Next, as shown in FIG. 5 d, the first passivation film 410 is formed onthe data line 300, the data pad 315, the source electrode 310, and thedrain electrode 320. The second passivation film 420 is patterned on thefirst passivation film 410.

The first passivation film 410 is formed on the entire surface of thesubstrate by the PECVD method.

The second passivation film 420 is formed in the thin film transistorregion. In more detail, the second passivation film 420 is patterned byexposure and developing processes after an organic insulating materialincluding a photo active compound (PAC) is deposited on the entiresurface of the substrate. The second passivation film 420 is patternedto have a hole constituting the first contact hole CH1.

Next, as shown in FIG. 5 e, to externally expose the drain electrode320, the first passivation film 410 region corresponding to the firstcontact hole CH1 region is etched to complete the first contact holeCH1. In this context, the first passivation film 410 region correspondsto a region exposed by the hole provided in the second passivation film420 over the first passivation film 410. The drain electrode 320 isexternally exposed by the first contact hole CH1. The first passivationfilm 410 is also etched in the gate pad region and the data pad region.

Next, as shown in FIG. 5 f, the pixel electrode 500 is patterned on thesecond passivation film 420. The pixel electrode 500 is patterned in thethin film transistor region, so as to be connected with the drainelectrode 320 through the first contact hole CH1.

Next, as shown in FIG. 5 g, the third passivation film 430 is formed onthe pixel electrode 500, and the sensing line 600 provided with thecontact portion 600 a is patterned on the third passivation film 430.

The third passivation film 430 is formed on the entire surface of thesubstrate by the PECVD method, and the sensing line 600 is patterned inthe thin film transistor region.

Next, as shown in FIG. 5 h, after the fourth passivation film 440 isformed on the sensing line 600, the second contact hole CH2, the thirdcontact hole CH3, and the fourth contact hole CH4 are formed.

The fourth passivation film 440 is formed on the entire surface of thesubstrate by the PECVD method.

The second contact hole CH2 is formed by etching a predetermined regionof the fourth passivation film 440, and the contact portion 600 a of thesensing line 600 is externally exposed by the second contact hole CH2.

The third contact hole CH3 is formed by etching predetermined regions ofthe gate insulating film 220, the third passivation film 430, and thefourth passivation film 440. The gate pad 215 is externally exposed bythe third contact hole CH3.

The fourth contact hole CH4 is formed by etching predetermined regionsof the third passivation film 430 and the fourth passivation film 440.The data pad 315 is externally exposed by the fourth contact hole CH4.

Next, as shown in FIG. 5 i, the common electrode 700, the gate padelectrode 750, and the data pad electrode 760 are patterned on thefourth passivation film 440.

The common electrode 700 is patterned in the thin film transistorregion, so as to be provided with a plurality of slits 710 therein.Particularly, the common electrode 700 is patterned to be connected withthe contact portion 600 a of the sensing line 600 through the secondcontact hole CH2.

The gate pad electrode 750 is patterned in the gate pad region, so as tobe connected with the gate pad 215 through the third contact hole CH3.

The data pad electrode 760 is patterned in the data pad region, so as tobe connected with the data pad 315 through the fourth contact hole CH4.

According to the aforementioned method of FIGS. 5 a to 5 i, when thefirst passivation film 410 is etched to externally expose the drainelectrode 320 during the process of FIG. 5 e, morphology of the data pad315 may be deteriorated due to exposure of the data pad 315 as shown inFIG. 6 a. For this reason, as shown in FIG. 6 b, when the fourth contacthole CH4 is formed by etching the predetermined regions of the thirdpassivation film 430 and the fourth passivation film 440 in accordancewith the process of FIG. 5 h, under cut may occur due to gas reflow. Asshown in FIG. 6 c, due to such under cut, a problem may occur in thatthe data pad electrode 760 may be opened when the data pad electrode 760is formed by the process of FIG. 5 i.

Hereinafter, a display device and a method of manufacturing the same,which may prevent under cut from occurring, will be described.

Second Embodiment

FIG. 7 is a cross-sectional view illustrating a display device accordingto the second embodiment of the present invention, and illustratescross-sections of lines A-A, B-B and C-C of FIG. 2. The line A-A of FIG.2 illustrates a thin film transistor region, the line B-B of FIG. 2illustrates a gate pad region, and the line C-C of FIG. 2 illustrates adata pad region.

As shown in FIG. 7, a gate electrode 210 and a gate pad 215 arepatterned on a substrate 100. The gate electrode 210 is formed in thethin film transistor region, and the gate pad 215 is formed in the gatepad region. The gate electrode 210 may be extended from theaforementioned gate line 200, and the gate pad 215 is connected with oneend of the gate line 200 through a gate in panel 2.

A gate insulating film 220 is formed on the gate electrode 210 and thegate pad 215. The gate insulating film 220 is formed on an entiresurface of the substrate except for a third contact hole CH3 region.

A semiconductor layer 230 and a data pad 315 are patterned on the gateinsulating film 220. The semiconductor layer 230 is formed in the thinfilm transistor region, and may be made of a silicon based semiconductormaterial or oxide semiconductor material. The data pad 315 is formed inthe data pad region, and is connected with one end of the aforementioneddata line 300.

A source electrode 310 and a drain electrode 320 are patterned on thesemiconductor layer 230. The source electrode 310 and the drainelectrode 320 are formed in the thin film transistor region. The sourceelectrode 310 is connected with the data line 300, and the drainelectrode 320 is spaced apart from the source electrode 310 while facingthe source electrode 310.

A first passivation film 410 is formed on the data line 300, the datapad 315, the source electrode 310, and the drain electrode 320. Namely,in the first embodiment, the first passivation film 410 is formed at aregion except for a first contact hole CH1 in the thin film transistorregion and is not formed in the gate pad region and the data pad region.However, in the second embodiment, the first passivation film 410 isformed on the entire surface of the substrate except for regions for thefirst contact hole CH1, a third contact hole CH3, and a fourth contacthole CH4. The first passivation film 410 may be made of an inorganicinsulating material such as a silicon nitride or a silicon oxide.

A second passivation film 420 is formed on the first passivation film410. the second passivation film 420 is formed in the thin filmtransistor region. The second passivation film 420 may not be formed inthe gate pad region and the data pad region. The second passivation film420 may be made of an organic insulating material such as acrylic resin,which includes a photo active compound (PAC). The second passivationfilm 420 may be formed at a thickness thicker than that of the firstpassivation film 410 and may serve to planarize the substrate.

A pixel electrode 500 is patterned on the second passivation film 420.The pixel electrode 500 is formed in the thin film transistor region.The pixel electrode 500 is connected with the drain electrode 320through the first contact hole CH1. The first contact hole CH1 is madeof combination of holes respectively formed in the first passivationfilm 410 and the second passivation film 420.

A third passivation film 430 is formed on the pixel electrode 500. Thethird passivation film 430 is formed on the entire surface of thesubstrate except for regions for the third contact hole CH3 and thefourth contact hole CH4. The third passivation film 430 may be made ofan inorganic insulating material such as a silicon nitride or a siliconoxide.

A sensing line 600 provided with a contact portion 600 a is patterned onthe third passivation film 430. The sensing line 600 is formed in thethin film transistor region.

A fourth passivation film 440 is formed on the sensing line 600. Thefourth passivation film 440 is formed on the entire surface of thesubstrate except for regions for a second contact hole CH2, the thirdcontact hole CH3, and the fourth contact hole CH4. The fourthpassivation film 440 may be made of an inorganic insulating materialsuch as a silicon nitride or a silicon oxide.

A common electrode 700, a gate pad electrode 750, and a data padelectrode 760 are patterned on the fourth passivation film 440. Thecommon electrode 700 is formed in the thin film transistor region, thegate pad electrode 750 is formed in the gate pad region, and the datapad electrode 760 is formed in the data pad region.

The common electrode 700, the gate pad electrode 750, and the data padelectrode 760 are formed on one layer by using one material by oneprocess.

The common electrode 700 is patterned to be provided with a plurality ofslits 710 therein. The common electrode 700 is connected with thecontact portion 600 a of the sensing line 600 through the second contacthole CH2 provided in the fourth passivation film 440.

The gate pad electrode 750 is connected with the gate pad 215 throughthe third contact hole CH3 formed by combination of holes respectivelyformed in the gate insulating film 220, the first passivation film 410,the third passivation film 430, and the fourth passivation film 440.

The data pad electrode 760 is connected with the data pad 315 throughthe fourth contact hole CH4 formed by combination of holes respectivelyformed in the first passivation film 410, the third passivation film430, and the fourth passivation film 440.

FIGS. 8 a to 8 j are cross-sectional views illustrating briefmanufacturing process steps of a substrate for a display deviceaccording to the second embodiment of the present invention, and relateto a process of manufacturing a substrate for the display device shownin FIG. 7.

First of all, as shown in FIG. 8 a, the gate electrode 210 and the gatepad 215 are patterned on the substrate 100. The gate electrode 210 isformed in the thin film transistor region, and the gate pad 215 isformed in the gate pad region.

The gate electrode 210 and the gate pad 215 may be patterned through aseries of mask processes, such as photoresist deposition, exposure,developing, etching, and strip after a thin film layer is deposited onthe substrate 100 by a sputtering method. A process of forming patternsof elements, which will be described hereinafter, may also be performedthrough the deposition of the thin film layer and the series of maskprocesses.

Next, as shown in FIG. 8 b, the gate insulating film 220 is formed onthe gate electrode 210 and the gate pad 215, and the semiconductor layer230 is patterned on the gate insulating film 220. The gate insulatingfilm 220 is formed on the entire surface of the substrate by a plasmaenhanced chemical vapor deposition (PECVD) method, and the semiconductorlayer 230 is formed in the thin film transistor region.

Next, as shown in FIG. 8 c, the source electrode 310 and the drainelectrode 320, which are connected with the data line 300, are patternedon the semiconductor layer 230, and the data pad 315 is patterned on thegate insulating film 220.

The source electrode 310 and the drain electrode 320 are formed in thethin film transistor region, and the data pad 315 is formed in the datapad region.

Next, as shown in FIG. 8 d, the first passivation film 410 is formed onthe data line 300, the data pad 315, the source electrode 310, and thedrain electrode 320. The second passivation film 420 is patterned on thefirst passivation film 410.

The first passivation film 410 is formed on the entire surface of thesubstrate by the PECVD method.

The second passivation film 420 is formed in the thin film transistorregion. In more detail, the second passivation film 420 is patterned byexposure and developing processes after an organic insulating materialincluding a photo active compound (PAC) is deposited on the entiresurface of the substrate. The second passivation film 420 is patternedto have a hole constituting the first contact hole CH1.

Next, as shown in FIG. 8 e, an etching stopper layer 800 is patterned onthe first passivation film 410 in the gate pad region and the data padregion. The etching stopper layer 800 is intended to prevent the datapad region from being etched when the first passivation film 410 isetched to form the first contact hole CH1 during a later process(process of FIG. 8 f). The etching stopper layer 800 is patterned byexposure and developing processes after an organic insulating materialincluding a photo active compound (PAC) is deposited on the entiresurface of the substrate.

Next, as shown in FIG. 8 f, the first passivation film 410 regioncorresponding to the first contact hole CH1 region, that is, the firstpassivation film 410 region exposed by the hole provided in the secondpassivation film 420 is etched, whereby the first contact hole CH1 iscompleted, and the etching stopper layer 800 is removed.

The drain electrode 320 is externally exposed by the first contact holeCH1.

Next, as shown in FIG. 8 g, the pixel electrode 500 is patterned on thesecond passivation film 420. The pixel electrode 500 is patterned in thethin film transistor region, so as to be connected with the drainelectrode 320 through the first contact hole CH1.

Next, as shown in FIG. 8 h, the third passivation film 430 is formed onthe pixel electrode 500, and the sensing line 600 provided with thecontact portion 600 a is patterned on the third passivation film 430.

The third passivation film 430 is formed on the entire surface of thesubstrate by the PECVD method, and the sensing line 600 is patterned inthe thin film transistor region.

Next, as shown in FIG. 8 i, after the fourth passivation film 440 isformed on the sensing line 600, the second contact hole CH2, the thirdcontact hole CH3, and the fourth contact hole CH4 are formed.

The fourth passivation film 440 is formed on the entire surface of thesubstrate by the PECVD method.

The second contact hole CH2 is formed by etching a predetermined regionof the fourth passivation film 440, and the contact portion 600 a of thesensing line 600 is externally exposed by the second contact hole CH2.

The third contact hole CH3 is formed by etching predetermined regions ofthe gate insulating film 220, the first passivation film 410, the thirdpassivation film 430, and the fourth passivation film 440. The gate pad215 is externally exposed by the third contact hole CH3.

The fourth contact hole CH4 is formed by etching predetermined regionsof the first passivation film 410, the third passivation film 430, andthe fourth passivation film 440. The data pad 315 is externally exposedby the fourth contact hole CH4.

Next, as shown in FIG. 8 j, the common electrode 700, the gate padelectrode 750, and the data pad electrode 760 are patterned on thefourth passivation film 440.

The common electrode 700 is patterned in the thin film transistorregion, so as to be provided with a plurality of slits 710 therein.Particularly, the common electrode 700 is patterned to be connected withthe contact portion 600 a of the sensing line 600 through the secondcontact hole CH2.

The gate pad electrode 750 is patterned in the gate pad region, so as tobe connected with the gate pad 215 through the third contact hole CH3.

The data pad electrode 760 is patterned in the data pad region, so as tobe connected with the data pad 315 through the fourth contact hole CH4.

According to the aforementioned method of FIGS. 8 a to 8 j, since theetching stopper layer 800 is patterned to prevent the gate pad regionfrom being etched during the process of FIG. 8 e, the number of masks isincreased, and the organic insulating material constituting the etchingstopper layer 800 may remain in the first contact hole CH1 region duringthe process of patterning the etching stopper layer 800. In other words,the etching stopper layer 800 is patterned by exposure and developingprocesses after the organic insulating material is deposited on theentire surface of the substrate, so that the organic insulating materialremains in the gate pad region and the data pad region only. At thistime, as shown in FIG. 9, the organic insulating material 900 may remainin the first contact hole CH1 region without being removed. If theorganic insulating material remains in the first contact hole CH1region, the first passivation film 410 region corresponding to the firstcontact hole CH1 region is not etched during the process of FIG. 8 f,thus preventing the first contact hole CH1 from forming properly.

Hereinafter, a display device and a method of manufacturing the same isdescribed in which a decreased number of masks are used relative to theabove described embodiment, and in which the problem of the organicinsulating material remaining in the first contact hole CH1 region isprevented.

Third Embodiment

FIG. 10 is a cross-sectional view illustrating a display deviceaccording to the third embodiment of the present invention, andillustrates cross-sections of lines A-A, B-B and C-C of FIG. 2. The lineA-A of FIG. 2 illustrates a thin film transistor region, the line B-B ofFIG. 2 illustrates a gate pad region, and the line C-C of FIG. 2illustrates a data pad region.

As shown in FIG. 10, a gate electrode 210 and a gate pad 215 are formedon a substrate 100. The gate electrode 210 is formed in the thin filmtransistor region, and the gate pad 215 is formed in the gate padregion. The gate electrode 210 may be extended from the aforementionedgate line 200, and the gate pad 215 is connected with one end of thegate line 200 through a gate in panel 2.

A gate insulating film 220 is formed on the gate electrode 210 and thegate pad 215. The gate insulating film 220 is formed on an entiresurface of the substrate except for a third contact hole CH3 region.

A semiconductor layer 230 is patterned on the gate insulating film 220.The semiconductor layer 230 is formed in the thin film transistor regionand the data pad region, and may be made of a silicon basedsemiconductor material or oxide semiconductor material.

A source electrode 310, a drain electrode 320, and a data pad 315 arepatterned on the semiconductor layer 230. The source electrode 310 andthe drain electrode 320 are formed on the semiconductor layer 230 in thethin film transistor region, and the data pad 315 is formed on thesemiconductor layer 230 in the data pad region. At this time, the datapad 315 is connected with one end of the aforementioned data line 300.The source electrode 310 is connected with the data line 300, and thedrain electrode 320 is spaced apart from the source electrode 310 whilefacing the source electrode 310.

Unlike the display device according to the first and second embodiments,in case of the display device according to the third embodiment, after amaterial layer (not shown) for forming the semiconductor layer 230 and asource/drain electrode layer (not shown) for forming the sourceelectrode 310/the drain electrode 320 are deposited in due order, sincethe source/drain electrode layer and the material layer aresimultaneously patterned by one process using a single mask, thesemiconductor layer 230 is formed below the data pad 315 even in thedata pad region as well as the thin film transistor region.

Also, in case of the display device according to the third embodiment,as described above, since the source/drain electrode layer and thematerial layer are simultaneously patterned using a single mask afterthe source/drain electrode layer is deposited on the material layer forforming the semiconductor layer 230, a tail of the semiconductor layer230 may be minimized.

A first passivation film 410 is formed on the data line 300, the sourceelectrode 310, and the drain electrode 320. The first passivation film410 is formed at a region except for an opening region H in the thinfilm transistor region, and is not formed in the gate pad regionprovided with the gate pad 215 and the data pad region provided with thedata pad 315. The first passivation film 410 may be made of an inorganicinsulating material such as a silicon nitride or a silicon oxide.

A second passivation film 420 is formed on the first passivation film410. The second passivation film 420 is formed in the thin filmtransistor region. The second passivation film 420 may be omitted (i.e.,not formed) in the gate pad region and the data pad region. The secondpassivation film 420 may be made of an organic insulating material suchas acrylic resin, which includes a photo active compound (PAC). Thesecond passivation film 420 may be formed at a thickness thicker thanthat of the first passivation film 410 and may serve to planarize thesubstrate.

The first passivation film 410 and the second passivation film 420 arestructured such that a hole exists through the first and secondpassivation films that at least partially exposes the source electrode310 and the drain electrode 320 from the first passivation film 410 andthe second passivation film 420.

A pixel electrode 500, a first passivation electrode 510, and a firstconnection electrode 520 are patterned on the second passivation film420. The pixel electrode 500 is formed in the thin film transistorregion and at least partially fills the hole through the firstpassivation film 410 and the second passivation film 420. Particularly,in case of the display device according to the third embodiment, after amaterial layer (not shown) for forming the pixel electrode 500 is formedon the patterned source/drain electrode layer exposed through theopening region H, the material layer for forming the pixel electrode 500and the source drain/electrode layer are partially removed when achannel of the thin film transistor is formed. Accordingly, in the thirdembodiment, the channel of the thin film transistor is formed in a statethat the material layer for forming the pixel electrode 500 and thesource drain/electrode layer are directly in contact with each otherbefore forming the channel unlike the first and second embodiments inwhich the pixel electrode 500 is connected with the drain electrode 320through the first contact hole CH1. As a result, the third embodimenthas a structure that the pixel electrode 500 is directly connected withthe drain electrode 320 via the hole through the first passivation film410 and the second passivation film 420. Furthermore, the pixelelectrode 500 contacts a region of the drain electrode 320 that is overat least a portion of the gate electrode 210. In other words, a planeperpendicular to the substrate through the region of the drain electrodeintersects the portion of the gate electrode 210. In accordance withthis structure, in the display device according to the third embodiment,transmittance is more improved than that of the display devicesaccording to the first and second embodiments.

The first passivation electrode 510 is patterned on a region of thesecond passivation film 420, over the source electrode 310, and servesto prevent the source electrode 310 from being damaged during theetching process for forming the channel of the thin film transistor.

The first connection electrode 520 is formed in the data pad region tocover the entire data pad 315. In more detail, the first connectionelectrode 520 is formed to cover the data pad 315, and is extended to aregion where the data pad 315 is not formed on the gate insulating film220.

Meanwhile, an auxiliary electrode 530 remains in the regioncorresponding to the second contact hole CH2 during the process offorming the pixel electrode 500 to form the sensing line 600, which willbe described later.

The pixel electrode 500, the first passivation electrode 510, the firstconnection electrode 520, and the auxiliary electrode 530 are formed onone layer using one material by one process.

The sensing line 600 provided with a contact portion 600 a is patternedon the auxiliary electrode 530. A second passivation electrode 610formed together with the sensing line 600 during the process ofpatterning the sensing line 600 is patterned on the first passivationelectrode 510, a third passivation electrode 620 is patterned on aregion of the pixel electrode 500, over the drain electrode 320, and asecond connection electrode 630 is patterned on the first connectionelectrode 520. The second connection electrode 630 is patterned in thesame shape as that of the first connection electrode 520.

The second passivation electrode 610 serves to prevent the sourceelectrode 310 from being etched during the process of forming thechannel, together with the first passivation electrode 510, and thethird passivation electrode 620 serves to prevent the pixel electrode500 and the drain electrode 320 from being etched during the process offorming the channel.

The second connection electrode 630 serves to connect a data padelectrode 760 with the data pad 315 together with the first connectionelectrode 520.

The sensing line 600, the second passivation electrode 610, the thirdpassivation electrode 620, and the second connection electrode 630 areformed on one layer using one material by one process.

A fourth passivation film 440 is formed on the sensing line 600, thesecond passivation electrode 610, the third passivation electrode 620,and the second connection electrode 630. Namely, the fourth passivationfilm 440 is formed on the entire surface of the substrate except forregions for the second contact hole CH2, the third contact hole CH3, andthe fourth contact hole CH4. The fourth passivation film 440 may be madeof an inorganic insulating material such as a silicon nitride or asilicon oxide.

A common electrode 700, a gate pad electrode 750, and the data padelectrode 760 are patterned on the fourth passivation film 440. Thecommon electrode 700 is formed in the thin film transistor region, thegate pad electrode 750 is formed in the gate pad region, and the datapad electrode 760 is formed in the data pad region. The common electrode700 at least partially fills the second contact hole CH2 through thefourth passivation film 440 such that the common electrode 700 isconnected with the sensing line 600 through the second contact hole CH2.The gate pad electrode 750 at least partially fills the third contacthole CH3 such that the gate pad electrode 750 is connected with the gatepad 215 through the third contact hole CH3. The data pad electrode 760at least partially fills the fourth contact hole such that the data padelectrode 760 is connected with the data pad 315 through the firstconnection electrode 520 and the second connection electrode 630 exposedthrough the fourth contact hole CH4.

In the display device of the third embodiment, the fourth contact holeCH4 is formed in a region of the fourth passivation film 440, which isnot overlapped with and is laterally offset from the data pad 315. Inother words, a plane perpendicular to the substrate through the fourthcontact hole CH4 does not intersect the data pad 315 in the thirdembodiment. Accordingly, in the display device of the third embodiment,the data pad 315 is prevented from being etched together with the fourthpassivation film 440 when the fourth passivation film 440 is partiallyremoved to form the fourth contact hole, whereby under cut may beprevented from occurring in the data pad 315.

The common electrode 700, the gate pad electrode 750, and the data padelectrode 760 are formed on one layer by using one material by oneprocess.

The common electrode 700 is patterned to be provided with a plurality ofslits 710 therein. The common electrode 700 is connected with thecontact portion 600 a of the sensing line 600 through the second contacthole CH2 provided in the fourth passivation film 440.

The gate pad electrode 750 is connected with the gate pad 215 throughthe third contact hole CH3 formed by combination of holes respectivelyformed in the gate insulating film 220, the first passivation film 410,the third passivation film 430, and the fourth passivation film 440.

The data pad electrode 760 is connected with the data pad 315 throughthe first connection electrode 520 and the second connection electrode630 exposed through the fourth contact hole CH4 formed in the regionwhich is not overlapped with and is laterally offset from the data pad315.

FIGS. 11 a to 11 j are brief cross-sectional views illustratingmanufacturing process steps of a substrate for a display deviceaccording to the third embodiment of the present invention, and relateto a process of manufacturing a substrate for the display device shownin FIG. 10.

As shown in FIG. 11 a, the gate electrode 210 and the gate pad 215 arepatterned on the substrate 100. The gate electrode 210 is formed in thethin film transistor region, and the gate pad 215 is formed in the gatepad region.

The gate electrode 210 and the gate pad 215 may be patterned through aseries of mask processes such as photoresist deposition, exposure,developing, etching, and strip after a thin film layer is deposited onthe substrate 100 by a sputtering method. A process of forming patternsof elements, which will be described hereinafter, may also be performedthrough the deposition of the thin film layer and the series of maskprocesses.

Next, as shown in FIG. 11 b, the gate insulating film 220 is formed onthe gate electrode 210 and the gate pad 215, a material layer forforming the semiconductor layer 230 and a source/drain electrode layerfor forming the source and drain electrodes are formed on the gateinsulating film 220. The material layer and the source/drain electrodelayer are patterned by one process using a single mask, whereby thesemiconductor layer 230 and a source/drain electrode layer pattern 330are formed. In this process, a first pattern is formed in a thin filmtransistor region comprising a first portion of the semiconductor layer230 and a first portion of the source/drain electrode layer pattern 330.A second pattern is formed in the data pad region comprising a secondportion of the semiconductor layer 230 and a data pad 315 formed from asecond portion of the source/drain electrode layer pattern 330.

The gate insulating film 220 is formed on the entire surface of thesubstrate by a plasma enhanced chemical vapor deposition (PECVD) method.

Next, as shown in FIG. 11 c, the first passivation film 410 is formed onthe source/drain electrode layer pattern 330 and the data pad 315, andthe second passivation film 420 is patterned on the first passivationfilm 410.

The first passivation film 410 is formed on the entire surface of thesubstrate by the PECVD method.

The second passivation film 420 is formed in the thin film transistorregion. In more detail, the second passivation film 420 is patterned byexposure and developing processes after an organic insulating materialincluding a photo active compound (PAC) is deposited on the entiresurface of the substrate. The second passivation film 420 is patternedto have an opening region H (i.e., a hole) for partially exposing thefirst passivation film 410 in the thin film transistor region.

Next, as shown in FIG. 11 d, the first passivation film 410 exposedthrough the opening region H and the first passivation film 410 regionformed in the gate pad region and the data pad region are removed byetching. Then, a material layer 500 a for forming the pixel electrode500 and a material layer 600 b for forming the sensing line 600 aredeposited on the entire surface of the substrate 100. As a result, thematerial layer 500 a for forming the pixel electrode 500 is directlyformed on the source/drain electrode layer pattern 330, whereby thepixel electrode 500 is directly in contact with the drain electrode 320even without a separate contract hole in the same manner as the processwhich will be described later.

Next, as shown in FIG. 11 e, after at least one of the material layer500 a for forming the pixel electrode 500 and the material layer 600 bfor forming the sensing line 600 is patterned on a region except for apredetermined region through a single process using a half tone mask, atleast a part of the source/drain electrode layer pattern 330 exposedthrough the opening region H is etched, whereby a channel region isformed. The source electrode 310 and the drain electrode 320 are formedon the semiconductor layer 230 by such etching of the source/drainelectrode layer pattern 330, whereby the thin film transistor iscompleted.

In this case, the predetermined region means a region where the sensingline 600 should be formed and the data pad region.

Accordingly, a pattern deposited with the auxiliary electrode 530 andthe sensing line 600, a pattern deposited with the first passivationelectrode 510 and the second passivation electrode 610, and a patterndeposited with the pixel electrode 500 and the third passivationelectrode 620 are formed in the thin film transistor region, a patternfor the pixel electrode 500 is formed in a transmissive region whereimages are displayed, and a pattern deposited with the first connectionelectrode 520 and the second connection electrode 630 is formed in thedata pad region.

Next, as shown in FIG. 11 f, after the fourth passivation film 440 isformed on the entire surface of the substrate 100, the second contacthole CH2, the third contact hole CH3, and the fourth contact hole CH4are formed.

The fourth passivation film 440 is formed on the entire surface of thesubstrate by the PECVD method.

The second contact hole CH2 is formed by etching a predetermined regionof the fourth passivation film 440, and the contact portion 600 a of thesensing line 600 is externally exposed by the second contact hole CH2.

The third contact hole CH3 is formed by etching predetermined regions ofthe gate insulating film 220 and the fourth passivation film 440, andthe gate pad 215 is externally exposed by the third contact hole CH3.

The fourth contact hole CH4 is formed by etching a predetermined regionof the fourth passivation film 440, and the second connection electrode630 is externally exposed by the fourth contact hole CH4. In oneembodiment, the fourth contact hole CH4 is formed on a region of thefourth passivation film 440, which is not overlapped with and islaterally offset from the data pad 315. As a result, the data pad 315may be prevented from being etched when the fourth contact hole CH4 isformed, whereby under cut of the data pad 315 may be prevented fromoccurring.

Next, as shown in FIG. 11 g, the common electrode 700, the gate padelectrode 750 and the data pad electrode 760 are patterned on the fourthpassivation film 440.

The common electrode 700 is patterned in the thin film transistorregion, so as to be provided with a plurality of slits 710 therein.Particularly, the common electrode 700 is patterned to be connected withthe contact portion 600 a of the sensing line 600 through the secondcontact hole CH2.

The gate pad electrode 750 is patterned in the gate pad region, so as tobe connected with the gate pad 215 through the third contact hole CH3.

The data pad electrode 760 is patterned in the data pad region, so as tobe connected with the data pad 315 through connection with the firstconnection electrode 520 and the second connection electrode 630 exposedthrough the fourth contact hole CH4.

According to the aforementioned method of FIGS. 11 a to 11 j, since thesource/drain electrode layer and the material layer for forming thesemiconductor layer 230 are patterned through one process after beingsequentially deposited, the number of masks is reduced by 1 as comparedwith the first embodiment. Since the material layer for forming thepixel electrode 500 and the material layer for forming the sensing line600 are patterned through one process after being sequentiallydeposited, the number of masks is additionally reduced by 1 as comparedwith the first embodiment. As a result, the display device may bemanufactured using six masks only. Accordingly, productivity may bemaximized through reduction of the manufacturing time.

Also, according to the method of FIGS. 11 a to 11 j, since under cutoccurring in the data pad may be solved even without use of additionalpassivation film, the number of masks may be reduced as compared withthe second embodiment that uses additional passivation film to preventunder cut from occurring, and the problem of the passivation filmremaining when additional passivation film is removed may be solvednaturally.

The substrate constituting the display device and the method ofmanufacturing the same have been described as above. The presentinvention includes various display devices, which may use theaforementioned substrate and the method of manufacturing the same, forexample, a liquid crystal display device, a plasma display panel, and anorganic light emitting display device, and a method of manufacturing thesame.

According to the present invention, the following advantages may beobtained.

As the common electrode is used as the sensing electrode for sensing atouch of the user, a separate touch screen is not required on thedisplay panel unlike the related art, whereby thickness is reduced, themanufacturing process is simplified, and the manufacturing cost isreduced.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A display device comprising: a thin filmtransistor in a pixel region having a gate line and a data line crossingthe gate line, the thin film transistor having a gate electrode, asemiconductor layer, a source electrode, and a drain electrode; a firstpassivation film on the thin film transistor; a second passivation filmon the first passivation film, the first and second passivation filmsstructured such that a hole exists through the first and secondpassivation films; a pixel electrode on the second passivation film andat least partially filling the hole through the first and secondpassivation films, the pixel electrode connected with the drainelectrode via the hole through the first and second passivation films; asensing line over the second passivation film; a common electrodeconnected with the sensing line; a data pad connected with one end ofthe data line; a first connection electrode on the data pad andconnected with the data pad; a second connection electrode on the firstconnection electrode and connected with the first connection electrode;and a data pad electrode having a same material as the common electrode,the data pad electrode connected with the data pad through the firstconnection electrode and the second connection electrode.
 2. The displaydevice of claim 1, further comprising: a third passivation film on thesensing line and the second connection electrode, the third passivationfilm structured such that a first contact hole and second contact holeexists through the third passivation film, the first contact hole atleast partially filled by the common electrode such that the sensingline is connected with the common electrode through the first contacthole, and the second contact hole at least partially filled by the datapad electrode such that the second connection electrode is connectedwith the data pad electrode through the second contact hole, wherein thesecond contact hole is in a region of the third passivation film that islaterally offset from the data pad.
 3. The display device of claim 1,wherein the pixel electrode is connected with a region of the drainelectrode via the hole through the first and second passivation films,the region over the gate electrode.
 4. The display device of claim 1,wherein the first connection electrode has a same material as the pixelelectrode, and the second connection electrode has a same material asthe sensing line.
 5. The display device of claim 1, wherein the sensingline is over the data line.
 6. The display device of claim 1, furthercomprising a first passivation electrode having a same material as thepixel electrode, the first passivation electrode on the secondpassivation film and the source electrode.
 7. The display device ofclaim 6, further comprising a second passivation electrode having a samematerial as the sensing line, the second passivation electrode on thefirst passivation electrode.
 8. The display device of claim 7, furthercomprising a third passivation electrode having the same material as thesensing line and the second passivation electrode, the third passivationelectrode on the pixel electrode.
 9. The display device of claim 8,wherein a third passivation film is on the semiconductor layer, thesecond passivation electrode, and the third passivation electrode in thehole through the first and second passivation films.
 10. The displaydevice of claim 1, further comprising an auxiliary electrode having asame material as the pixel electrode, the auxiliary electrode interposedbetween the second passivation film and the sensing line.
 11. A displaydevice comprising: a thin film transistor in a pixel region having agate line and a data line crossing the gate line, the thin filmtransistor having a gate electrode, a semiconductor layer, a sourceelectrode, and a drain electrode; a first passivation film on the thinfilm transistor; a second passivation film on the first passivationfilm, the first and second passivation films structured such that a holeexists through the first and second passivation films; a pixel electrodeon the second passivation film and the drain electrode and at leastpartially filling the hole through the first and second passivationfilms, the pixel electrode connected with the drain electrode via thehole through the first and second passivation films; a data padconnected with one end of the data line; a first connection electrode onthe data pad and connected with the data pad; a second connectionelectrode on the first connection electrode and connected with the firstconnection electrode; and a data pad electrode on the second connectionelectrode, the data pad electrode connected with the data pad; and asensing line on the second passivation film, the sensing line over thedata line.
 12. The display device of claim 11, wherein the pixelelectrode contacts a region of the drain electrode via the hole throughthe first and second passivation films, wherein the region is over thegate electrode.
 13. The display device of claim 11, further comprising afirst passivation electrode having a same material as the pixelelectrode, the first passivation electrode on the second passivationfilm and the source electrode.
 14. The display device of claim 13,further comprising a second passivation electrode having a same materialas the sensing line, the second passivation electrode on the firstpassivation electrode.
 15. The display device of claim 14, furthercomprising a third passivation electrode having the same material as thesensing line and the second passivation electrode, the third passivationelectrode on the pixel electrode.
 16. The display device of claim 15,further comprising a wherein the third passivation film on the sensingline and the second connection electrode, the third passivation film onthe semiconductor layer, the second passivation electrode, and the thirdpassivation electrode in the hole through the first and secondpassivation films.
 17. The display device of claim 11, furthercomprising an auxiliary electrode having a same material as the pixelelectrode, the auxiliary electrode interposed between the secondpassivation film and the sensing line.
 18. The display device of claim11, wherein the first connection electrode has a same material as thepixel electrode, and the second connection electrode has a same materialas the sensing line.